Many men undergo a semen analysis to determine a possible cause of infertility. If you're trying to conceive, but aren't succeeding, your doctor might recommend a semen analysis. In this procedure, a sample of semen is analyzed for volume, pH (P-H), concentration, motility, morphology, vitality, and white blood cells. According to the World Health Organization, in 'normal' sperm, 75 percent should be living, and 50 percent or more should move in a forward direction. Sometimes if you don't have enough sperm concentration, your odds of fertilization are significantly reduced. If your sperm don't have enough motility in the right direction, the chances of successful fertilization are lowered as well. Just because you have a low sperm count or motility doesn't necessarily mean that you can't reproduce, it just means you have lower odds at success.